This invention is directed to a device for the treatment of constricted ducts in human bodies. More particularly, this invention is directed to a vascular or coronary stent and a system for inserting or implanting it.
Numerous stents are known to be useful for insertion into the body. Known stents include balloon expandable stents, as represented, for example, by U.S. Pat. Nos. 5,108,416, 4,735,665, and 4,739,762, as well as self-expandable stents formed from coiled material. See, for example, U.S. Pat. Nos. 4,913,141, 4,768,507, and 4,580,568. With regard to any of these stents, particularly the coiled stents, expansion normally causes the length of the stents to decrease during insertion or implantation. This can be a distinct disadvantage with regard to precise positioning of such stents. There is a definite need for stents that either shorten only a minimal amount or shorten in a predictable manner, to facilitate more precise positioning within the body.
It is an object of this invention to provide a stent for treating constricted ducts.
It is also an object of this invention to provide a vascular or coronary stent and a system for deploying same.
It is a further object of this invention to provide a wound coil stent which does not significantly shorten along its length during deployment of the stent, or shortens in a predictable manner.
These and other objects of the invention will become more apparent in the discussion below.